Breather Hole- Basic Understanding

Breather Hole- Basic Understanding

Window seat of the aircraft is favourite seat of almost all of us aircraft nerds. Ordinary peoples will just see scenery from aircraft window. But we aircraft nerds observe various things of aircraft such as movement of various elements of aircraft wings such as slits, flaps, ailerons, etc then aircraft engine, etc.

Have you ever take a look on the small hole at the bottom of aircraft window? If not then next time whenever you will travel by plane just take a look at that small hole at the bottom of aircraft window.

The purpose of the small bleed hole in the [middle] pane is to allow pressure to equilibrate between the passenger cabin and the air gap between the panes, so that the cabin pressure during flight is applied to only the outer pane," Marlowe Moncur, director of technology at GKN Aerospace – a passenger window manufacturing company

So that means that if the outer pane somehow was broken by debris, we'd still have the middle pane to protect us from the lack of air pressure outside. Sure, it'd have a small hole in it, but that's nothing the plane's pressurisation system couldn't compensate for.

During ascent and descent of aircraft the pressure keeps varying,the breather hole keeps the pressure same between the layers of the window and prevent the window from exploding or imploding.

While this tiny hole plays an important role in keeping us safe, it also helps keep the window panes from fogging up – a result of the temperature difference between the inside and outside of the cabin – allowing us to stare out into the clouds.

This small hole is known as breather hole or bleed hole. There are mainly two purpose of this hole

*Controlling moisture

*Equalizing pressure difference

Small air gap is present between outer & middle pane.

This tiny hole let moisture escape from air gap & prevent aircraft window by fogging up or by frosting. And let passengers enjoy the outer scenery.

As stated breather hole also help to equalizing pressure difference. As aircraft ascends atmospheric pressure decreases & cabin pressure is maintained by cabin pressure stabilizer system as outer atmospheric low pressure is not good for human health. This causes pressure difference between cabin & atmosphere.

Which produces lots of physical stress on aircrafts window which can damage aircraft windows. So to prevent this damage breather hole is used. Breather hole equalize the pressure difference between inner & outer aircraft window pane by releasing some amount of pressure in air gap. So outer pane takes lots of pressure & middle pane acts as fail safe. If outer pane got damaged due to some reason air get leaked from breather hole & prevent middle pane by damaging.

This is why breather hole is used!!

Prepared by: Air.Net Team